Process for extracting fats from textiles



Patented July 19, 1927.

UNITED STATES PATENT OFFICE.

ALBERT BEIL, OI HOCHBT-ON-THE-KAIN, AND WILHELI MEYER, OI HERS- IEL'D, GERMANY ASSIGNOBS TO A. BECEBEBG GESELLSCHAIT HIT BESGHBANK- TEB HAI'TUNG AND GEOBG BBA'UN GESELLSCHAIT HIT BESCHRANKTEB HAI- mG, BOTH OF HEBSFELD, GERMANY.

rnocass iron 'nxrnac'rme ra'rs raox ran-mas.

' 8'0 Drawing. Application fled Karen 11, 1928, Serial Io. 84,095, and in Germanylaroh 18, 1925.

The removal of fats from textiles by means of organic extraction agents is a problem which has often been discussed without, hitherto, a generally utilizable solution bein found. Conse uently it continued to be e ected, almostwit out exception, by :means of aqueous alkaline treatment. It is quite obvious that the removal of fat by organic solvents would be given the preference, if it 10 were possible to carry out the 'de-fattin'g without danger of fire or explosion; under the utmost possible care to prevent deterioration of the fibres; without danger to the necessary apparatus and, above all, economically.

Methylenechloride has been shown to satisfy these requirements in a surprisingly erfect manner. Its employment as solvent orms therefore the subject of the present invention. 0

Chlorinated hydrocarbons have been repeatedly suggested for the de-fattin of textiles, firstly on account of their sa eness in respect of fire, but also because the de-fatting is accompanied by very considerable improvement of the fibres. For example in the de-fattin of raw wool the fat of the surfaceonly is issolved out while the interior of the fibres remainsmndisturbed and the 80 fibres retain, therefore, their resiliency and pliability.

The hydrocarbons employed hitherto all exhibit the disadvantage that in conse uence ,of the catalytic formation of hydroe loric acid gas they damage the apparatus, a disadvantage which has hitherto not been successfully obviated. In contradistinction thereto methylenechloride is distinguished by an extraordinary resistance in res ect of ac- 40 tion thereon by heated contact su stances, a

circumstance which qualifies methylenechloride to serve excellently as a de-fatting agent. In addition the low boiling point of methylenechloride is also favorable since the heating of the apparatus does not need to be too intense,

The low boiling point of meth lenechloride is also of advantage, in anot er direction, for the de-fatting of textiles. With many textiles, such as for example wool and silk, the heating for the driving off of the solvent must,-as far as possible, not exceed C. which is not feasible with the solvents of higher boiling point. Even if a vacuum is employed it is not possible, in the case of the solvents of higher boiling-point to prevent, if the said solvents are to be removed completely, a portion of the material treated from being too strongly heated, and, in this manner, becoming brittle and weak. Insuflicient heating, however, results, with the very voluminous textiles, in considerable quantities of solvent remaining in the ma- 'terial and being lost.

On account of its stability towards decomgeosmg influences and because it can easily removed without residue from the material to be de-fatted the employment of methylene-chloride for the de-fatting of textiles is economically feasible in contradistinction to the chlorinated hydrocarbons recommended heretofore. I

EmampZa-IOOO kilograms of raw-wool is treated once or several times with say from 6000 to 8000 liters of liquid methylenechloride in a rotary extraction apparatus of 10 cubic meters capacit After drawing off the major portion 0 the solventand dis solved fats, hot water at 50 C. is caused to flow through the heating jacket oftheextractor and the apparatus is rotated quite slowly. Such heating drives ofi a large portion of the solvent retained by the wool. The residue of the solvent is then removed with the assistance of a vacuum.

What we claim as new and desire to secure by Letters Patent is v 1. In a method of defatting textiles by means of volatile solvents, the .tep of treatin such textiles with liquid methylenechlo- 90 n e. I 2. A method of defatting textiles which consists in eulojeoting such textiles to the solvent notion of liquid methylenechloride, olnewing ofi' the major portion of the solvent and dissolved fats, subsequently heating the textiles to temperatures not exceeding 50 G, to voletilize and remove therefrom the major portion of the solvent retained by the tentiles end]. finally applying e vacuum to rema enta move the residual solvent from such textiles.

In testimony that we claim the foregoing as our invention, We have signed our names this 26th day of February, 1926.

ALBERT BEE. W'ILHELM ADOLF MEYER. 

